A FORMULA FOR THE CALCULATION 

 OF ROCK FILL DIKES 



EDITOR'S NOTE 



Within the past year or two there has been considerable discussion 

 among shore control and harbor engineers regarding the merits of the 

 Iritarren formula for calculating the sizes of stone and related slopes 

 of riprap structures for resisting wave actiono Through the efforts of 

 MTo Ro Oo Eatonj South Pacific Dii/isionj Corps of Engineers and the 

 courtesy of the University of California it is possible to publish the 

 following translation of Iribarren's paper in which the development of 

 the formula is discussed o The paper was translated by Mr,, Do Heinrich, 

 University of California and has been edited by DTo Mo Ao Masonj Beach 

 Erosion Boardo 



In view of the intense interest in the paper and to develop in one 

 publication the pertinent comments on the formula the Bulletin will 

 welcome comments for publication from interested engineers » Comments 

 should be addressed to The Bulletin, Beach Erosion Boardj, 5201 Little 

 Falls Road, No W, Washington 16, Do Co, and should reach that office 

 not later than 1 March 194^9 » 



■s;- •?!- ■»• 



Eduardo de Castro published in the Revista de Obras Publicas, 

 April 15 5 1933, a most interesting article entitled "Rock-fill Dams and 

 Dikes/' in which he presented a formula fixing the slope and size of 

 stone in rock-fill dikes necessary to resist satisfactorily the violent 

 beatings of the seao 



De Castro begins his article by stating: 



"It is not for me to dare that which others of more standing 

 and reputation have not dared to do — authors of universal renown 

 hesitate when the moment arrives to determa.ne the slope of a rock- 

 fill dam beaten by the waves^ and justify their doubts and hesita- 

 tion by the great difficulties which the problem holdSooooThe 

 unknown force of the waves, the anomalies of storms, and the heavy 

 and grievous replies with which the sea responds to the science 

 and prudence of the builders, show that they are righto oo oLikewise 

 at the conclusion of these lines one will have the impression that 

 the problem is very obscure and only the ignorant can believe that 

 it is solvedooooBut in spite of all, and until the definite truth 

 is known there need not be lacking provisional truths, or better 

 said, approximations to the truth o" 



The equation which I have formulated is a provisional truth in an 

 advance toward the definite trutho The reasoning upon which it is 

 based follows: 



